1. Field of the Invention
The invention relates to a communication device.
2. Description of the Related Art
A communication device is provided with a connector by which a communication cable is connected to the device. For example, a jack connector conforming to the RJ45 standard is used as the connector.
In the connector, as electrodes (terminals) are arranged relatively close to each other, as compared with transmission lines formed on a circuit board, a crosstalk tends to have a significant effect. The crosstalk which is caused at the connector becomes a major problem along with the increasing of communication speed in recent years.
For example, as a method to decrease the crosstalk caused at the connector, a method to exchange alignment of the transmission lines connected to the connector is known.
The arrangement of electrodes in the jack connector used as the connector is standardized by TIA/EIA-568-B defined by American National Standards Institute (ANSI) such that number 1 and number 2 electrodes, number 3 and number 6 electrodes, number 4 and number 5 electrodes, and number 7 and number 8 electrodes are paired respectively.
The communication device is provided with number 1 to number 8 transmission lines corresponding to number 1 to number 8 electrodes. If the transmission lines are arranged in serial order, especially, crosstalk between the pair of number 3 and number 6 transmission lines and the other pairs increases.
Accordingly, by exchanging the arrangement of the transmission lines in the pair of number 3 and number 6 or by exchanging the arrangement of transmission lines in the other pairs than the pair of number 3 and number 6 transmission lines, the crosstalk caused at the connector can be cancelled by the crosstalk caused at the transmission lines so as to decrease the crosstalk.
Further, the prior art document information relevant to the invention may include JP-A-2010-27437.